Methods of extending the life of battery

ABSTRACT

Methods for extending the life of a battery output regulated voltages from output terminals configured to interface with input terminals of battery powered devices. A method includes receiving a battery electrical power output from the battery. The voltage output by the battery decreases from a battery first output voltage to a battery second output voltage during use of the battery. The electrical power output is used to drive a converter that outputs a converter electrical power having a converter output voltage greater than the battery second output voltage. The converter electrical power is output from output terminals configured to interface with input terminals of a battery powered device. The converter is configured and supported relative to the battery to interface with one or more output terminals of the battery.

CROSS-REFERENCES TO RELATED APPLICATIONS

The present application is a Continuation U.S. Non-Provisionalapplication Ser. No. 14/531,392, filed Nov. 3, 2014, which claims thebenefit of U.S. Provisional Application No. 61/962,131, filed Nov. 1,2013, and is a Continuation-in-Part of U.S. application Ser. No.13/236,436, filed Sep. 19, 2011, which claims the benefit of U.S.Provisional Application No. 61/403,625, filed Sep. 20, 2010, the fulldisclosures of which are incorporated herein in their entirety byreference.

BACKGROUND

The invention relates in general to battery technology and moreparticularly to techniques for extending the operational life ofbatteries such as disposable and rechargeable batteries. Most consumerelectronic equipment use batteries. Batteries are classified in terms ofprimary batteries of dry cells, secondary batteries and rechargeablebatteries. Many of electronic equipment are sensitive and need veryprecise voltages to operate properly. In some cases, if the batterysupplying voltage to electronic equipment drops too low, not only doesthe equipment provide unreliable output, but the low voltage could alsodamage the equipment. As such, many manufacturers of electronicequipment include circuitry that detects battery voltage levels and ifthe voltage level drops below a certain level, the circuit would turnitself off. As an example, a fresh unused AA battery provides 1.5V. Overtime, as the battery charge is consumed by the equipment that utilizethe battery, the battery voltage starts to drop.

Some electronic equipment that use disposable batteries, such as AAbatteries, are designed to stop operating when the battery voltage dropsby 10% or so. That means when the voltage of an AA battery drops toabout 1.4V or 1.35V, the battery is no longer useable by the equipmentand has to be replaced with a fresh battery. Thus, the entire voltagerange between 0V to 1.35V is wasted, resulting in significantinefficiency. This is akin to the scenario where only 10% of a sodabottle is consumed, as a matter of routine, and the rest discarded. Thisclearly would be very wasteful and inefficient.

Another factor impacting the cost of batteries is that some of thematerial used in manufacturing batteries are difficult to mine and insome cases are considered rare earth materials. The price of thesematerials have been on the rise since some are only found in countrieslike China, and China has started limiting the export of thesematerials.

In addition to the adverse economic impacts of battery inefficiencies,there are significant environmental impacts. There are about 3 billionbatteries sold every year. Batteries pose a special environmental riskbecause they contain toxic material that can find their way into ournatural resources such as ground water. They also are not biodegradable.Many nations as well as municipalities have laws and local ordinancesabout recycling of batteries. Furthermore, the carbon footprintassociated with manufacturing and distribution of batteries raisesconcerns. The process of mining these materials, putting them in thebatteries, packaging the batteries, and shipping them all over the worldtakes a lot of energy and generates a lot of greenhouse gases. Thus,improving the use efficiency of batteries provides significant economicas well as environmental benefits.

Thus, there is a need for techniques that improve the efficiency ofbatteries such as disposable and rechargeable batteries.

BRIEF SUMMARY

Embodiments of the invention provide techniques for significantlyincreasing the life of batteries. In accordance with one embodiment, abattery sleeve for extending the operational life of one or morebatteries, includes a positive conductive electrode and an insulatinglayer extending below the conductive electrode such that when the sleeveis coupled to a battery, the positive conductive electrode is positionedabove the positive terminal of the battery with the insulating layerelectrically isolating the positive conductive electrode from thepositive terminal of the battery.

In another embodiment, the battery sleeve further includes a negativeconductive electrode configured so that when the sleeve is coupled to abattery, the negative conductive electrode is in electrical contact withthe negative terminal of the battery.

In another embodiment, the battery sleeve further includes a voltageregulator circuit adapted to receive the positive and negative terminalsof a battery and provide an output signal on an output terminalelectrically connected to the positive conductive electrode.

In another embodiment, the battery sleeve includes a voltage regulatorcircuit adapted to receive the positive and negative voltages providedby the battery and generate a substantially constant output voltage onthe battery sleeve's positive conductive electrode for the duration ofthe battery's operating life.

In another embodiment, the voltage regulator is housed in an upperportion of the battery sleeve near the positive conductive electrode. Inan alternate embodiment, the voltage regulator is housed in a lowerportion of the battery sleeve near the negative conductive electrode.

In another embodiment, when the battery sleeve is coupled to a battery,the positive conductive electrode of the sleeve serves as the newpositive terminal of the battery.

In another embodiment, the battery sleeve is configured so that when thesleeve is coupled to a battery, the positive terminal of the battery iscovered by the insulating layer such that the positive terminal is notexternally electrically accessible.

In yet another embodiment, the battery sleeve is configured so that whenthe sleeve is coupled to a battery, the negative terminal of the batteryis externally electrically accessible.

In accordance with another embodiment of the invention, a battery sleevefor extending the operational life of one or more batteries, includes apositive conductive electrode configured such that when the batterysleeve is coupled to at least one battery, the positive conductiveelectrode of the sleeve serves as the new positive terminal of the atleast one battery.

In one embodiment, the battery sleeve further includes a voltageregulator adapted to receive the voltage provided by the at least onebattery and generate a substantially constant output voltage for theduration of the operating life of the at least one battery

In another embodiment, the battery sleeve further includes an insulatinglayer extending below the conductive electrode, wherein the sleeve isconfigured such that when the sleeve is coupled to a battery, thepositive conductive electrode is positioned above the positive terminalof the battery with the insulating layer insulating the positiveconductive electrode from the positive terminal of the battery.

In another embodiment, the battery sleeve further includes a negativeconductive electrode configured so that when the sleeve is coupled to abattery, the negative conductive electrode is in electrical contact withthe negative terminal of the battery.

In another aspect, a method is provided for extending the life of abattery. The method includes receiving a battery electrical power outputfrom the battery. The battery electrical power output has a batteryoutput voltage that decreases from a battery first output voltage to abattery second output voltage. The battery electrical power output isused to drive a converter that outputs a converter electrical powerhaving a converter output voltage greater than the battery second outputvoltage. The converter electrical power is output from one or moreoutput terminals configured to interface with one or more inputterminals of a battery powered device. The converter can be configuredand supported relative to the battery to interface with one or moreoutput terminals of the battery. The converter can be embedded withinthe battery and the converter electrical power output outputted viaterminals of the battery.

In many embodiments of the method, the converter output voltage has asubstantially constant magnitude as the battery output voltage decreasesfrom the battery first output voltage to the battery second outputvoltage. The battery second output voltage can be less than 70 percentof the battery first output voltage.

The method can include directly outputting the battery electrical powerwhen the battery is producing a voltage exceeding a voltage required bya device powered by the battery. For example, the method can includeoutputting the battery electrical power output from the one or moreoutput terminals configured to interface with one or more inputterminals of a battery powered device as the battery output voltagedecreases from the battery first output voltage to a voltage equal to orgreater than a minimal voltage level that the battery powered devicerequires to operate normally.

To further extend the life of the battery, the method can includeoutputting a decreased voltage relative to a nominal voltage or avoltage initially produced by the battery. For example, the method caninclude decreasing the converter output voltage during at least aportion of the decrease of the battery output voltage from the batteryfirst output voltage to the battery second output voltage. For example,the converter output voltage can decrease by less than 10 percent andthe battery output voltage decreases by greater than 30 percent duringthe portion of the decrease of the battery output voltage from thebattery first output voltage to the battery second output voltage. Asanother example, the converter output voltage can be less than thebattery output voltage during an initial portion of the decrease of thebattery output voltage from the battery first output voltage to thebattery second output voltage.

In many embodiments of the method, the converter includes a step-upconverter and a step-down converter. The step-up converter and thestep-down converter can be controlled such that the converter outputvoltage is: a) less than the first voltage, b) greater than the secondvoltage, and c) varies by less than 10 percent as the battery outputvoltage decreases from the battery first output voltage to the batterysecond output voltage. The battery second output voltage can be lessthan 70 percent of the battery first output voltage.

The method can be practiced using any suitable battery and/orcombination of suitable batteries. For example, the battery supplyingthe battery electrical power output can include separate batteriesconnected in series. As another example, the battery can be a 9 voltbattery having standardized adjacent output terminals. As yet anotherexample, the battery can have an exterior shell and the converter can bedisposed within the exterior shell.

The method can include preventing polarity reversal. For example, themethod can include preventing polarity reversal by blocking matingbetween a negative terminal of the battery and a positive input voltageterminal of the converter.

In another aspect, a battery sleeve for extending the operational lifeof one or more batteries is provided. The battery sleeve includes apositive conductive electrode, an insulating layer, and a voltageregulation circuit. The insulating layer extends below the conductiveelectrode such that when the sleeve is coupled to the one or morebatteries, the positive conductive electrode is positioned above apositive terminal of the one or more batteries with the insulating layerelectrically isolating the positive conductive electrode from thepositive terminal. The voltage regulation circuit is adapted to receivea voltage provided by the one or more batteries and generate anincreased output voltage on the positive conductive electrode relativeto the provided voltage for at least a portion of the operating life ofthe one or more batteries. In many embodiments, the voltage provided bythe one or more batteries decreases over the operational life of the oneor more batteries from a battery first output voltage to a batterysecond output voltage that is less than 70 percent of the battery firstoutput voltage.

In many embodiments of the battery sleeve, to further extend the life ofthe battery, the voltage regulation circuit can output a decreasedvoltage relative to a nominal voltage or a voltage initially produced bythe battery. For example, the voltage regulation circuit can output thevoltage provided by the one or more batteries to the positive conductiveelectrode as the voltage provided by the one or more batteries decreasesfrom a battery first output voltage to a voltage equal to or greaterthan a minimal voltage level that the battery powered device requires tooperate normally. As another example, the voltage regulation circuit cangenerate an output voltage greater than the voltage provided by the oneor more batteries, the output voltage generated by the voltageregulation circuit decreasing during a portion of the operating life ofthe one or more batteries. For example, the voltage generated by thevoltage regulation circuit can decrease by less than 10 percent and thevoltage provided by the one or more batteries decreases by greater than30 percent during the portion of the operating life of the one or morebatteries in which the voltage generated by the regulation circuitdecreases. As another example, the voltage generated by the voltageregulation circuit can be less than the voltage provided by the one ormore batteries during an initial portion of the operating life of theone or more batteries.

In many embodiments of the battery sleeve, the voltage regulationcircuit includes a step-up converter and a step-down converter. Thestep-up converter and the step-down converter are controlled such thatthe voltage generated by the voltage regulation circuit is: a) less thanan initial voltage provide by the one or more batteries during theoperating life of the one or more batteries, b) greater than a finalvoltage provided by the one or more batteries at the end of theoperating life of the one or more batteries, and c) varies by less than10 percent during the operating life of the one or more batteries. Thefinal voltage provided by the one or more batteries can be less than 70percent of the initial voltage provided by the one or more batteries.

The battery sleeve can be configured for use with any suitable batteryand/or combination of suitable batteries. For example, the one or morebatteries can include two or more batteries connected in series. The oneor more batteries can include a 9 volt battery having standardizedadjacent output terminals.

The battery sleeve can be configured to prevent inadvertent polarityreversal from incorrect coupling of the battery sleeve with the one ormore batteries. For example, the battery sleeve can include a u-shapedelement configured to accommodate the positive terminal of the one ormore batteries when the battery sleeve is coupled with the one or morebatteries and to block electrical connection between the voltageregulation circuit and a negative terminal of the one or more batteriesso as to prevent polarity reversal in the voltage provided by the one ormore batteries to the voltage regulation circuit.

In another aspect, a battery assembly having an extended operating lifeis provided. The battery assembly includes an outer shell, one or morevoltage generating cells disposed within the outer shell and providingan output voltage, a positive voltage terminal, a negative voltageterminal, and a voltage regulation circuit disposed within the outershell. The voltage regulation circuit receives the output voltageprovided by the one or more voltage generating cells and generates anincreased output voltage relative to the voltage provided by the one ormore voltage generating cells over at least a portion of an operatinglife of the one or more voltage generating cells. The voltage regulationcircuit is operatively connected to the positive and negative voltageterminals to output the generated increased output voltage via thepositive and negative voltage terminals.

In another embodiment, a voltage regulation circuit is incorporatedwithin a battery-powered device. The voltage regulation circuit isconfigured to extend the life of one or more batteries used to power thebattery-powered device by outputting a voltage that is equal to orexceeds a minimum voltage required to operate the battery-powered devicenormally even when the one or more batteries output a voltage that isless than the minimum voltage required to operate the battery-powereddevice normally.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a battery regulation system 110 according to oneembodiment;

FIG. 2 shows a simplified diagram of a battery sleeve according to oneembodiment;

FIG. 3 shows a side view of a battery sleeve coupled to a battery,according to one embodiment;

FIG. 4 shows a simplified diagram of a battery sleeve with the regulatorcircuit placed along a bottom portion of the sleeve according to oneembodiment;

FIG. 5 is a simplified diagram showing an embodiment wherein a batterysleeve is adapted to couple to two serially-connected batteries;

FIGS. 6A and 6B show yet another embodiment wherein the regulator andthe sleeve are adapted so that the sleeve provides the positive terminalof the battery to external devices together with a regulated outputvoltage; and

FIG. 7 shows actual measurements that illustrate the advantages of thevarious embodiments.

FIG. 8A shows an inverted exploded view of a battery sleeve with aregulator circuit placed to interface with a positive terminal of abattery, in accordance with an embodiment.

FIG. 8B shows a battery and associated insertion path of the battery forcoupling the battery with the battery sleeve of FIG. 8A.

FIG. 8C shows the battery of FIG. 8B coupled with the battery sleeve ofFIG. 8A.

FIGS. 8D, 8E, and 8F illustrate a battery sleeve configurationconfigured to prevent polarity reversal, in accordance with anembodiment.

FIGS. 9A and 9B show regulator assemblies configured for use with anine-volt battery, in accordance with an embodiment.

FIGS. 10A and 10B shows a battery that includes a regulator circuitdisposed within an exterior shell of the battery, in accordance with anembodiment.

FIG. 11 illustrates a two-phase voltage regulation approach having abypass phase, in accordance with an embodiment.

FIG. 12 illustrates a voltage regulation approach utilizing both voltageincrease and decrease relative to battery output voltage, in accordancewith an embodiment.

FIG. 13 illustrates a three-phase voltage regulation approach includinga voltage variation phase, in accordance with an embodiment.

FIG. 14 is a simplified diagram showing a voltage regulation circuitincluding a step-up converter, a bypass circuit, and a filter circuit,in accordance with an embodiment.

FIG. 15 is a simplified diagram showing a step-down converter circuit,in accordance with an embodiment.

FIG. 16 is a simplified diagram showing a voltage regulation circuitincluding a step-up converter, a step-down converter, a filter, and abypass circuit, in accordance with an embodiment.

FIG. 17 is a circuit diagram showing a voltage regulation circuit forproviding a stepped up voltage and a native bypassed voltage, inaccordance with an embodiment.

FIG. 18 is a diagram showing an electronic device incorporating avoltage regulation circuit, in accordance with an embodiment.

DETAILED DESCRIPTION

In the following description of the present embodiments, reference ismade to the accompanying drawings that form a part hereof, and in whichis shown by way of illustration specific embodiments in which theembodiments may be practiced. These embodiments are described insufficient detail to enable those skilled in the art to practice theinvention, and it is to be understood that other embodiments may beutilized and that process, electrical or mechanical changes may be madewithout departing from the scope of the present disclosure. Thefollowing detailed description is, therefore, not to be taken in alimiting sense.

FIG. 1 shows a battery regulation system 110 according to oneembodiment. Positive terminal 104 of battery 103 is connected to inputterminal 101 of voltage regulator 105. Ground terminal 100 of battery103 is connected to ground input terminal 106 of voltage regulator 105.In one embodiment, negative terminal 100 of the battery needs to berouted to where voltage regulator 105 is physically located. This couldbe accomplished via a flexible PCB that forms part of a battery sleevewhich is described in more detail further below. Output terminal 102 ofvoltage regulator 105 provides the output of battery regulation system110. There is an insulator placed between positive terminal 104 ofbattery 103 and output 102 of voltage regulator 105.

The operation of battery regulation system 110 is described next. In oneexemplary embodiment of system 110, output 102 of system 110 isregulated to 1.5V. A fresh AA battery provides a voltage to regulator105 in the range of 1.5V to 1.6V. Output 102 of regulator 105 is thenregulated to 1.5V, and thus the output of battery regulation system 110is fixed to 1.5V. In operation, as the device that uses batteryregulation system 110 consumes current from battery 103, the batterygradually loses the charge that was originally placed in the batterythru chemical energy storage means. This causes the voltage output bybattery 103 to decline over time. Regulator 105 however keeps providinga constant 1.5V at output terminal 102 even though the input voltage ofthe regulator is reduced below 1.5V. This in effect provides a constantvoltage to the device that uses battery regulation system 110 until thevoltage provided by battery 103 is reduced to the minimum voltageregulator 105 can operate with. In this example, that would be around0.7V to 0.8V. This allows the end device to utilize battery 103 for alonger period of time. Also, a lot more of the stored charge in thebattery is used before it is discarded.

FIG. 2 shows a simplified diagram of battery sleeve 200 according to oneinvention. Sleeve 200 when coupled to battery 103 covers the battery'stop terminal 104. Sleeve 200 has an upper portion that fits snug aroundthe upper portion of battery 103. Sleeve 200 is generally designed toensure minimal increase in the overall dimension of the battery whencoupled to the battery. Sleeve 200 contains an insulator (not shown)which electrically isolates positive terminal 104 of battery 103 fromthe new positive terminal 204 of battery sleeve 200. Sleeve 200 alsoincludes a bottom section which includes a bottom conductor 205 thatelectrically connects to negative terminal 100 of battery 103. One ormore conductive traces 202 route bottom conductor 205 to the regulatorcircuit (not shown) housed in the upper part of sleeve 200.

FIG. 3 shows a side view of sleeve 300 coupled to battery 103, accordingto one embodiment. Sleeve 300 wraps around the top part of battery 103,and has a top conductor electrode 304 insulated from positive terminal104 of battery 103 by insulator 312. In this embodiment, regulator 105is housed in the upper part of sleeve 300. A conductive trace 306extending in sleeve 300 connects input terminal 101 of regulator 105 topositive terminal 104 of battery 103. Another conductive trace 310extending in sleeve 300 connects negative terminal 100 of battery 103 toinput terminal 106 of regulator 105. Yet a third conductive traceextending in sleeve 300 connects output terminal 102 of regulator 105 tothe sleeve's top conductor electrode 304. Conductive traces 306, 308 and310 are insulated from one another. As described earlier, in operation,top conductive electrode 304 serves as the battery's “new” positiveterminal.

In an alternate embodiment shown in FIG. 4, regulator 405 is placed in abottom portion of sleeve 400 close to where negative terminal 100 ofbattery 103 would be located when battery 103 is inserted in sleeve 400.In this embodiment, positive terminal 104 of battery 103 is routed by aconductive trace 412 extending through sleeve 400 to the bottom of thesleeve where regulator 405 resides. Conductive trace 412 routed to thebottom is connected to input terminal 101 of regulator 405, and theother input 106 of regulator 405 receives the negative terminal 100 ofbattery 103 which is present at the bottom of sleeve 400. Outputterminal 102 of voltage regulator 405 is then routed up by conductivetrace 414 and connected to top conductor electrode 404 of sleeve of 400.As in prior embodiments, the top conductor electrode 404 of the sleeveis insulated form positive terminal 104 of battery 103 by an insulatinglayer 410. In this embodiment, two conductive trances 412, 414 extendbetween the upper and lower portions of sleeve 400.

FIG. 5 is a simplified diagram showing an embodiment wherein sleeve 500is adapted to couple to two serially-connected batteries 103A, 103B. Inthis exemplary embodiment, batteries 103A, 103B are AA batteriesproviding a 3V output. Regulator 505 is shown in FIG. 5 outside sleeve500 to minimize clutter. In practice, regulator 505 is housed in sleeve500. Regulator 505 is used in a similar manner to the above embodiments.As in previous embodiments, as the voltage of the two batteries drop dueto use, regulator 505 provides a constant regulated voltage equivalentto the doubled voltage of fresh batteries.

FIGS. 6A and 6B show yet another embodiment wherein the regulator andthe sleeve are adapted so that the sleeve provides the positive terminalof the battery to external devices together with a regulated outputvoltage. FIG. 6A shows how positive terminal 104 and negative terminal100 of battery 103 are interconnected with the voltage regulator 605.The regulator is shown separate from the sleeve for clarity, though inpractice the regulator would be housed in the sleeve. FIG. 6A alsodepicts insulator 610 which insulates bottom electrode 612 of the sleevefrom negative terminal 100 of battery 103. FIG. 6B more accuratelyreflects the physical location of regulator 605, which is along thebottom of the sleeve. In this embodiment, output 102 of voltageregulator 605 is used as a series voltage to the voltage of the battery.In the beginning when the battery is fresh, output 102 of voltageregulator 605 is set to 0V, or even negative, to make sure the voltageprovided by the sleeve to external equipment remains at 1.5V. As thebattery charge drops over time, voltage regulator 605 maintains avoltage at its output 102 substantially equal to 1.5V−V(Battery). Inother words, the regulator monitors the voltage provided by battery 103and if it falls below the regulated voltage, it then generates a voltageto compensate for the drop in the battery voltage. As an example, as thebattery is used and its voltage drops to 1.1V, voltage regulator 605provides a voltage of 0.4V at its output 102.

In accordance with embodiments of the invention, a battery sleeve whencoupled to a battery, isolates the positive terminal of the battery fromexternal devices, and during operation, regulates the battery voltage toa constant voltage and provides the regulated constant voltage in placeof the original battery voltage to external devices. An advantage ofsuch a battery sleeve is that even after the output voltage of thebattery drops below the allowable operating voltage of the externalequipment, the external equipment continues to receive a constantvoltage and thus continues to operate and draw charge from the battery.It would continue doing so until such time that the output voltage ofthe battery drops below the range that the voltage regulation system canoperate. In the AA battery example, without the battery sleeve, thebattery needs to be thrown away when it drops from 1.5V to 1.4V or1.35V. However, with the sleeve, the battery voltage can drop to as lowas 0.8V or 0.7V while the external equipment continues to see 1.5V. Itis noted that the current level of the battery sleeves need to be inline with the current needs of the end system.

If one looks at the potential return of such a device in terms oflifetime of a battery, one can see significant benefits. For instance,the AA battery in the above example would use roughly the equivalentcharge of the battery output in the range of 1.5V to 1.4V. This meansthat after 0.1V drop, the battery's life is over. If the battery couldbe used until its voltage reaches 0.8V, then after 0.7V drop thebattery's life is over. If one were to assume that the time versus thevoltage drop is a linear function, then the life of the battery could beimproved by a factor of 7 in this example. However, advantageously thetime versus voltage drop is not quite linear. The time it takes for thebattery voltage to drop by 0.1V is longer at lower voltages versus athigher voltages. That means that if a constant current was drawn fromthe battery, it would take the battery a lot longer to discharge from1.2V to 1.1V than it would from 1.5V to 1.4V. This means that the extentto which the battery life is increased could be even higher than thefactor of 7 in the above example above.

It is noted that the regulation circuit has a certain efficiency whichcuts back on the extent to which the battery life is extended though thelife time reduction is rather minimal. During operation, the regulatoritself uses a certain amount of current from the battery. A lot of theavailable DC to DC converters have high efficiencies of around 95%. Thatis, of power supplied by the battery, 5% is used by the converter andthe rest is available for the end user. However, the 5% efficiency lossdue to use of a converter, when compared to the 700% gain in efficiencyof the battery, is negligible. It is further noted, that the converterefficiency may drop as the battery voltage drops due to use. Forexample, as the battery voltage drops from 1.5V to 1V, the efficiency ofthe converter may drop down to 50% to 60%. However, 50% efficiency isstill a significant improvement over the current approach of discardingthe batteries because their voltage has dropped below the operablevoltage range (i.e., 1.4-1.5V).

The economics of the present invention are attractive. While there maybe some cost associate with implementing the present invention, suchcost is more than off-set by cost savings achieved in extending the lifea battery to equivalent of 5 to 7 batteries. The implementation can beexternal to the battery as described in various embodiments above oralternatively battery manufacturers could incorporate the regulatorcircuit and the associated connections inside the battery-housing duringthe manufacturing process. However, the attachable sleeve implementationhas the added advantage that it can be used over and over again. Thatis, once the battery inside the sleeve is completely used up, the usedup battery could be tossed and another battery could be placed insidethe sleeve. So, the cost of the sleeve is spread among many batteriesthus minimizing the added cost per battery. The attachable sleeve hasthe added benefit (over the implementation where the regulator isincorporate inside batteries) that the existing battery manufacturingprocesses, equipment, and factories do not need to be changed.

It is noted that the battery compartment of most, if not all, electronicequipment need not be retrofit to accommodate the battery sleeves. Whilethe sleeve slightly increases the height of the battery, the spring inbattery compartments used to hold the battery in place can accommodatethe added height. The length of the spring is typically in the range of5 mm to 10 mm. The height increase of the battery due to the sleeve isabout 1 mm. The extra height is easily accommodated by the springcompressing one more millimeter when the battery with the sleeve isinserted in the battery compartment. The thickness of the sleeve couldof course be reduced as technology advances. For batteries such as 9Vbatteries where both positive and negative terminals are located alongthe same end of the battery, the sleeve would have even less of animpact on the size of the battery. That is because for such batteries,the sleeve is simply a male to female converter with an insulator toisolate the battery's positive terminal from the output of the voltageregulator.

In another embodiment, multiple batteries could be placed in series andone sleeve can encompass the series of batteries, such as that shown inFIG. 5. As described with the FIG. 5 embodiment, the output voltage ofthe serially connected batteries would be used as input to the voltageregulator and the constant output voltage provided by the regulator isprovided to external devices. It is noted that the life of such seriallyconnected batteries is increased even more than the case of a singlebattery, as explained next. A single AA battery, when used without thesleeve, would be tossed when its voltage drops from 1.5V to 1.35V. Whenused with the sleeve, the battery can be used down to 0.8V. If thebattery discharge time was linearly related to the discharge rate of thebattery, then the life extension time would be 0.7V/0.15V or more than 4times. In contrast, in the case where two AA batteries are seriallyconnected and no sleeve is used, the two batteries would need to betossed when the voltage of the serially connected batteries drops from3V to 2.7V. When used with a sleeve, the serially connected batteriescan be used from 3V down to 0.8V. The life extension time would then beproportional to (3−0.8)/(3−2.7)=2.2/0.3 which results in battery lifeextension of over 7 times. This assumes a linear relationship betweenthe output voltage and time. However, as explained above, batteriesbehave non-linearly in that the time it takes to drop by 0.1V from 1.5Vto 1.4 v is much shorter than the time it takes to go from 1.3 v to 1.2v. This advantageously further increases the battery life when a sleeveis used.

In yet another embodiment, the apparatus of the current invention isused in conjunction with rechargeable batteries. There is a phenomenonwith rechargeable batteries called shadow effects. If a battery isdischarged by a small amount and then fully charged, and if that processis repeated numerous times, the battery loses its ability to holdcharge. The current embodiments enable the rechargeable batteries tooperate for a much longer time and hence reduce the need to recharge bythe end user as frequently.

Another known phenomenon is that if a rechargeable battery is allowed todischarge beyond a certain limit, the number of times that it can becharged is reduced dramatically. The current embodiments include avoltage detection system that detects when the battery reaches the lowerlimit and shuts off the output voltage, hence increasing the number oftimes the battery can be charged.

In one embodiment, printed silicon on metal technology can be used toimplement the sleeve, the regulator circuitry and its associatedconnections. There is new technology that uses material other thansilicon to process circuitry. These types of printed silicon, which insome cases are printed on stainless steel, could be used to shape thesleeve that goes around the battery. It would also allow for betterthermal characteristics.

In yet another embodiment, a flexible PCB could be used to routeterminals from one side of the battery to the other side. Theseflexible, thin layers would allow the sleeve to be very thin.

In yet another embodiment, the efficiency of the regulator system couldbe adjusted such that while the system would allow for the maximumcurrent output capability of the regulator system to be quite high, theefficiency would be maximum at the output current level that the endsystem usually runs. For example, if the battery is used in a remotecontrol system, where the average current consumption of the remotecontrol system is 50 mA, then the voltage boosting system, which may bea DC to DC conversion system, is set to be as high as possible at thatoutput current level.

FIG. 7 shows measurements that illustrate the advantages of the variousembodiments. Three popular AA battery brands, Panasonic, Duracell andSony were chosen for the measurements. Active load circuitry that drew afixed 50 mA current was placed at the output of these batteries and thevoltage of each battery was measured over time. The horizontal accessshows time and the vertical access shows the battery voltage. Thestarting voltage for these fresh batteries was 1.6V. The amount of timeit takes for the batteries to reach 1.39V, which is where a lot ofelectronic equipment stop operating, are listed. The Panasonic batterytook 6.3 hours to reach that level, while it took 4.5 hours for the Sonybattery. The Panasonic battery when used in conjunction with aregulator, according to embodiments of the invention, took 27.9 hoursbefore it stopped providing 1.5V, and the Sony battery when used with aregulator took 32 hours before its stopped providing 1.5V. Thus, withthe regulator, it takes 4.5 to 7 times longer before the battery needsto be replaced. Thus, the total number of batteries that need to bemanufactured and consequently discarded would be reduced by 4 to 7times. This would have a significant impact on our planet if one takesinto account the carbon footprint for extracting all the batterymaterial, their manufacturing, their transportation to stores, theirpackaging as well as all of the toxic material that end up in ourlandfills.

FIG. 8A shows an inverted exploded view of a battery sleeve assembly 700that includes a regulator circuit 705 placed to interface with apositive terminal of a battery and a battery sleeve 710, in accordancewith an embodiment. The regulator circuit 705 can be formed on asuitable substrate (e.g., organic based, ceramic based, a flexibleprinted circuit (FPC), a rigid-flexible printed circuit (RFPC). Theregulator circuit 705 can be configured in accordance with any suitableregulator circuit described herein and provide corresponding regulation.The sleeve 710 supports the substrate and can be configured to fit overany suitable standard battery (e.g., AA, AAA, C, D) as illustrated inFIGS. 8B and 8C. The sleeve 710 can be made from a conductive materialthat is coated with a non-conductive material except where the sleeve710 is electrically connected to the regulator circuit 705 and where thesleeve 710 contacts the negative terminal of the battery. Thenon-conductive material coating prevents electrical shorting between thenegative terminal with any metal cylinder wall of a battery-operateddevice such as in a flashlight. The sleeve 710 includes a side portion712, a bottom portion 714, and a top portion 716. The side portion 712has cylindrical inner and outer surfaces separated by a thickness (e.g.,less than 1 mm) that is selected to provide adequate strength andstiffness while being thin enough to enable the combination of thebattery sleeve assembly 700 and the battery to be installed withinbattery-operated devices configured to accommodate the battery.

The top of the regulator circuit 705 has a spring contact 718. Thespring contact 718 is configured to extend the overall length of thebattery and also to be deflectable to become completely flat whenconnecting two batteries physically in series. The configuration of thespring contact 718 enables the combination of the battery and thebattery sleeve assembly 700 to fit within battery powered devicesconfigured to house the battery even with the addition of the batterysleeve assembly 700. FIG. 8C shows the combination of the batteryinstalled into the battery sleeve assembly 700.

FIGS. 8D, 8E, and 8F illustrate a battery sleeve configurationconfigured to prevent polarity reversal, in accordance with anembodiment. FIG. 8D shows the battery sleeve assembly 700 with anencapsulation element 719 configured to prevent inadvertent polarityreversal. The encapsulation element 719 has a u-shaped configurationshaped to accommodate mating of a positive battery terminal with apositive input contact on the substrate 705 while blocking mating of anegative battery terminal with the positive input contact on thesubstrate 705. FIG. 8E shows a close-up view of the substrate 705 andthe encapsulation element 719. FIG. 8F shows a close-up exploded view ofthe substrate 705 and the encapsulation element 719. The encapsulationelement 719 can be formed from a suitable non-conductive encapsulationmaterial and can further serve to protect battery sleeve components suchas regulator circuit components located on the substrate 705 fromcontact induced damage.

FIG. 9A shows a regulator assembly 720 configured for use with anine-volt battery 721, in accordance with an embodiment. The regulatorassembly 720 includes a female input voltage connector 722 configured tocouple with the male positive terminal 723 of the battery 721, a maleinput voltage connector 724 configured to couple with the femalenegative terminal 725 of the battery 721, a substrate assembly 726, amale positive voltage output terminal 727, and a female negative voltageoutput terminal 728. The substrate assembly 726 includes a regulatorcircuit 729. The regulator circuit 729 is electrically connected to thefemale input voltage connector 722 and the male input voltage connector724 so as to receive output voltage and current from the battery 721.The regulator circuit 729 outputs a regulated voltage to the outputterminals 727, 728 using any suitable approach such as described herein.

FIG. 9B shows another regulator assembly 730 configured for use with anine-volt battery 721, in accordance with an embodiment. The regulatorassembly 730 is similar to the regulator assembly 720 described above,but includes a lower base plate 731 and an upper base plate 732. Thelower base plate 731 supports the input voltage connectors 722, 724. Theupper base plate 732 supports the output terminals 727, 728. Theregulator circuit 729 is sandwiched between the upper and lower baseplates 731, 732, thereby being protected from incidental contact damage.

FIGS. 10A and 10B shows a battery 740 that includes a regulator circuit742 disposed within an exterior shell of the battery 740, in accordancewith an embodiment. The regulator circuit 742 can be configured similarto the other regulator circuits described herein. The regulator circuit742 can be embedded within the battery using any suitable approach toisolate the regulator circuit 742 from substances within the battery.For example, the regulator circuit 742 can be embedded within a pottingmaterial such as a suitable resin, silicone, a ultraviolet light curableacrylic potting compound, polyester, a hot melt material, etc. Theregulator circuit 742 can also be embedded via a suitable castingprocess, via encapsulation or dip coating, and via encapsulation viaprinted circuit board (PCB) conformal coating.

FIG. 11 illustrates a two-phase regulation approach 750 having a bypassphase 752 and a boost phase 754, in accordance with an embodiment. Inthe bypass phase 752, the battery output voltage 756 is greater than orequal to a selected voltage level 757 (e.g., 1.5 volts as illustrated).Any suitable voltage (e.g., 1.55 volts, 1.50 volts, 1.45 volts, etc.)can be used as the selected voltage level 757. In many instances, afully charged battery will output a voltage in excess of its nominalvoltage rating. In the illustrated example, the battery output voltage756 is 1.60 volts at time zero and decreases over time to 1.50 volts atabout 5 minutes of use and further to 0.80 volts at about 46 minutes ofuse. While the battery output voltage 756 is greater than or equal tothe selected voltage level 757, the regulator circuit outputs thebattery output voltage 756 directly via a suitable bypass circuit asdescribed herein. After the battery output voltage 756 drops below theselected voltage level 757, the battery output voltage 756 is used todrive the regulator circuit, which outputs the selected voltage level757 during the boost phase 754. By utilizing the bypass phase 752 whilethe battery output voltage is equal to or greater than the selectedvoltage level 757, power losses associated with boosting the batteryoutput voltage are avoided during the bypass phase 752.

FIG. 12 illustrates a regulation approach 760 utilizing both voltageincrease and decrease relative to battery output voltage, in accordancewith an embodiment. In the example shown, a battery output voltage 762decreases over time during an example use from 1.60 volts at time zeroto a selected voltage level 764 (e.g., 1.40 volts in the illustratedexample) at about 12 minutes of use and to 0.80 volts at about 48minutes of use. During a first phase 766, the selected voltage 764output by a regulator circuit to a battery-powered device is decreasedrelative to the battery output voltage 762 used to drive the regulatorcircuit. For example, the regulator circuit can include a step-downconverter circuit as described herein to output a decreased outputvoltage relative to the battery output voltage 762 during the firstphase 766. During a second phase 768, the selected voltage 764 output bya regulator circuit to a battery-powered device is increased relative tothe battery output voltage 762 used to drive the regulator circuit. Forexample, the regulator circuit can further include a step-up convertercircuit as described herein to output an increased output voltagerelative to the battery output voltage 762 during the second phase 768.

FIG. 13 illustrates a three-phase regulation approach 770 that includesa bypass phase 772, a voltage variation phase 774, and a constantvoltage phase 776. During the bypass phase 772, a battery output voltage778 is directly output by a regulator circuit to a battery powereddevice as described herein. The bypass phase is used where the batteryoutput voltage 778 exceeds a first selected voltage level (e.g., 1.45volts in the illustrated example). Any suitable voltage level can beused as the first selected voltage level. When the battery outputvoltage 778 is below the first selected voltage level and above a secondselected voltage level (e.g., 1.00 volts in the illustrated example),the battery output voltage 778 is used to drive a regulator circuit thatis controlled to output a varying output voltage 780. In the illustratedexample, the varying output voltage 780 decreases from 1.50 volts whenthe battery output voltage 778 is 1.45 volts down to 1.35 volts when thebattery output voltage 778 is 1.0 volts. During the constant voltagephase 776, the battery output voltage 778 is used to drive the regulatorcircuit that is controlled to output a constant output voltage 782(e.g., 1.35 volts in the illustrated example). By decreasing the amountof voltage boost supplied by the regulator circuit, the efficiency ofthe regulator circuit is improved thereby yielding increased effectivebattery life.

FIG. 14 is a simplified diagram showing a voltage regulation circuit 800including a step-up converter 802, a bypass circuit 804, and a filtercircuit 806, in accordance with an embodiment. The voltage regulationcircuit 800 can be used to provide the functionality described hereinwith respect to extending the life of a battery. The step-up convert 802receives output from a battery 808 and outputs a regulated voltage tothe filter circuit 806, which then delivers a smoothed voltage output toa battery-powered device 810. The filter circuit 806 can include anysuitable combination of one or more inductors and/or capacitors tosmooth voltage variations in the voltage output by the step-up converter802.

The step-up converter 802 includes an inductor 812, a diode 814, acapacitor 816, a controlled switch 818 (e.g., a MOSFET), and a switchcontroller 820. The switch controller 820 regulates the resulting ratiobetween the voltage output by the step-up converter 802 and the voltagesupplied by the battery 808 via controlled opening and closing of theswitch 818. When the switch 818 is closed, current flowing through theinductor 812 increases. When the switch 818 is opened, the inductor 812drives a decreasing current amount through the diode 814, which resultsin a charging of the capacitor 816, which boosts the voltage supplied tothe filter circuit 806 and thus to the battery-powered device 810relative to the voltage output by the battery 808. The diode 814 servesto prevent discharging of the capacitor 816 via backflow of currentthrough the switch 181 when the switch 818 is closed. By cycling theswitch 818 between opened and closed at a rate selected to providedesired charge levels to the capacitor 816, a controlled increase involtage supplied to the battery-powered device 810 relative to thevoltage output by the battery 808 is produced.

The switch controller 820 controls the opening and the closing of theswitch 818 via a control lead 822 connected with the switch 818. Theswitch controller 820 controls the switch 818 in accordance with voltageinputs 824, 824 from the battery 808 and voltage inputs 828, 830 fromthe voltage output by the voltage regulation circuit 800 to thebattery-powered device 810. For example, the switch controller 820 caninclude any suitable control electronics (e.g., a microprocessor, amicrocontroller, etc.) that employs a suitable approach (e.g., via alookup table) for varying the off-on duty cycle of the switch 818 tooutput desired voltage levels to the battery-powered device 810 asdescribed herein for the varying voltages output by the battery 808during the battery's life.

The bypass circuit 804 includes a bypass switch 832 that is controlledby the switch controller 820 via a control lead 834. By closing thebypass switch 832 and opening the step-up converter switch 818, thebattery output voltage can be supplied directly to the battery-powereddevice 810 in accordance with the bypass phase described herein.

FIG. 15 is a simplified diagram showing a step-down converter circuit850, in accordance with an embodiment. The step-down converter circuit850 is operable to reduce the voltage supplied to a battery-powereddevice 810 from a battery 808 so as to extend the life of a battery, forexample, during the first phase 766 described with reference to thevoltage regulation approach illustrated in FIG. 12.

The step-down converter circuit 850 includes an inductor 852, acapacitor 854, a diode 856, a controlled switch 858, and a switchcontroller 860. The switch controller 860 controls opening and closingof the switch 858 via a control lead 862. When the switch is closed,current flows through the inductor 852 at an increasing rate. If theswitch remains in the closed position, the voltage supplied to thebattery-powered device 810 increases to reach the voltage output by thebattery 808. When the switch 858 is open, the voltage supplied to thebattery-powered device 810 is provided via discharge of the capacitor854. If the switch remains in the open position, the voltage supplied tothe battery-powered device 810 will reduce to zero over time. By cyclingthe switch 858 between open and closed at a rate selected to providedesired charge levels to the capacitor 854, a desired decrease involtage supplied to the battery-powered device 810 relative to thevoltage output by the battery 808 is produced.

The switch controller 860 controls the opening and the closing of theswitch 858 via a control lead 862 connected with the switch 858. Theswitch controller 860 controls the switch 858 in accordance with voltageinputs 864, 866 from the battery 808 and voltage inputs 868, 870 fromthe voltage output by the voltage regulation circuit 850 to thebattery-powered device 810. For example, the switch controller 860 caninclude any suitable control electronics (e.g., a microprocessor, amicrocontroller, etc.) that employs a suitable approach (e.g., via alookup table) for varying the off-on duty cycle of the switch 858 tooutput desired voltage levels to the battery-powered device 810 asdescribed herein for the varying voltages output by the battery 808during the battery's life.

FIG. 16 is a simplified diagram showing a voltage regulation circuit 900that includes a step-up converter 902, a step-down converter circuit904, a filter 906, and a bypass circuit 908, in accordance with anembodiment. The step-up converter 902 receives voltage output by abattery 808 and output a regulated voltage to the step-down converter904. The step-up converter 902 is configured to controllably increasethe voltage output from the step-up converter relative to the voltagesupplied by the battery 808. In the illustrated embodiment, thestep-down converter 904 receives voltage output by the step-up converter902 and outputs a regulated voltage to the filter 906. Alternatively,the positions of the converters 902, 904 can be reversed with thestep-down converter 904 receiving voltage from the battery 808 andoutputting regulated voltage to the step-up converter 902. The filter906 is configured to smooth the regulated voltage supplied to the filterand output a smoothed regulated voltage to the battery-powered device810. Any suitably configured step-up converter 902 can be employed, suchas the step-up converter 802 described herein. Any suitably configuresstep-down converter 904 can be employed, such as the step-down converter850 described herein. The bypass circuit 908 is configured and functionsimilar to the bypass circuit 804 described herein.

FIG. 17 is a circuit diagram showing a voltage regulation circuit 950for providing a stepped up voltage and a native bypassed voltage, inaccordance with an embodiment. The voltage regulation circuit 950 can beused in any suitable method or device described herein. The voltageregulation circuit 950 receives an input voltage via an input voltageconnection 952 and outputs an output voltage via an output voltageconnection 954. The voltage regulation circuit 950 is connected to aground 956 (e.g., a negative terminal of a battery to which the inputvoltage connection 952 is connected).

The voltage regulation circuit 950 functions similar to the voltageregulation circuit 800 illustrated in FIG. 14 and described above. Thevoltage regulation circuit includes an inductor 958, an input sidecapacitor 960, a control unit 962, output side capacitors 964, 966, andoutput side resistors 968, 970. While the input voltage received via theinput voltage connection 952 is greater than or equal to a target outputvoltage to be supplied to a battery powered device via the outputvoltage connection 954, the control unit 962 can electrically connectthe (Vout) terminal with the (Vin) terminal, thereby outputting theinput voltage received from the battery to the output voltage connection954. When the input voltage received via the input voltage connection952 is less than the target output voltage, the control unit 962alternately connects the (SW) input terminal with the (GND) outputterminal and the (Vout) output terminal, thereby causing a suitablecurrent flow through the inductor 958, which then drives current outthrough the (Vout) terminal, thereby causing accumulation of charge onthe output side capacitors 964, 966, thereby boosting the voltagesupplied to the output voltage connection 954 in a manner similar as todescribed herein with respect to the voltage regulation circuit 800. Theinput side capacitor 960 serves to reduce variation in the input voltagesupplied to the inductor 958 and the control unit 962.

The voltage regulation circuits can be included within a battery powereddevice so as to extend the life of one or more batteries used to powerthe battery-powered device. For example, FIG. 18 shows a battery-powereddevice 1000 that includes a voltage regulation circuit 1002 includedtherein. The voltage regulation circuit 1002 can be configured similarto the other regulator circuits described herein. The battery-powereddevice 1000 includes a circuit and/or element 1004 that is powered byone or more batteries 1004, which can be removable, replaceable, and/orrechargeable. As with the other regulation circuits described herein,the voltage regulation circuit 1002 is configured to extend the life ofthe one or more batteries 1004 by outputting a regulated voltage for usein powering the circuit and/or element 1004 even when the voltage outputby the one or more batteries 1004 falls below a minimum voltage requiredfor normal operation of the circuit and/or element 1004.

Although specific embodiments have been illustrated and describedherein, it will be appreciated by those of ordinary skill in the artthat any arrangement that is calculated or designed to achieve the samepurposes may be substituted for the specific embodiments shown. Manyadaptations of the disclosure will be apparent to those of ordinaryskill in the art. For example, the configuration and/or functionalitydescribed herein with regard to any of the voltage regulator 105, theregulator 405, the regulator 505, the voltage regulator 605, theregulator circuit 705, the regulator circuit 729, the regulator circuit742, the voltage regulation circuit 800, the step-down converter circuit850, the voltage regulation circuit 900, the voltage regulation circuit950, and the functionality described herein, such as the functionalitydescribed herein with respect to FIG. 11 through FIG. 13, can beemployed alone or in any suitable combination in a method and/or devicefor extending the life of a battery. Accordingly, this application isintended to cover any adaptations or variations of the disclosure.

What is claimed is:
 1. A method for extending the life of a battery, the method comprising: receiving a battery electrical power output from the battery, the battery electrical power output having a battery output voltage that decreases from a battery first output voltage to a battery second output voltage; using the battery electrical power output to drive a converter that outputs a converter electrical power having a converter output voltage greater than the battery second output voltage; and outputting the converter electrical power from one or more output terminals configured to interface with one or more input terminals of a battery powered device, the converter being (a) configured and supported relative to the battery to interface with one or more output terminals of the battery, or (b) embedded within the battery, wherein the converter electrical power output is outputted via terminals of the battery.
 2. The method of claim 1, wherein: the converter output voltage has a substantially constant magnitude as the battery output voltage decreases from the battery first output voltage to the battery second output voltage; and the battery second output voltage is less than 70 percent of the battery first output voltage.
 3. The method of claim 1, further comprising outputting the battery electrical power output from the one or more output terminals configured to interface with one or more input terminals of a battery powered device as the battery output voltage decreases from the battery first output voltage to a voltage equal to or greater than a minimal voltage level that the battery powered device requires to operate normally.
 4. The method of claim 1, further comprising decreasing the converter output voltage during at least a portion of the decrease of the battery output voltage from the battery first output voltage to the battery second output voltage.
 5. The method of claim 4, wherein the converter output voltage decreases by less than 10 percent and the battery output voltage decreases by greater than 30 percent during the portion of the decrease of the battery output voltage from the battery first output voltage to the battery second output voltage.
 6. The method of claim 1, wherein the converter output voltage is less than the battery output voltage during an initial portion of the decrease of the battery output voltage from the battery first output voltage to the battery second output voltage.
 7. The method of claim 1, wherein: the converter comprises a step-up converter and a step-down converter that are controlled such that the converter output voltage is: a) less than the first voltage, b) greater than the second voltage, and c) varies by less than 10 percent as the battery output voltage decreases from the battery first output voltage to the battery second output voltage; and the battery second output voltage is less than 70 percent of the battery first output voltage.
 8. The method of claim 1, wherein the battery comprises a plurality of separate batteries connected in series.
 9. The method of claim 1, wherein the battery is a 9 volt battery having standardized adjacent output terminals.
 10. The method of claim 1, wherein the battery has an exterior shell and the converter is disposed within the exterior shell.
 11. The method of claim 1, further comprising preventing polarity reversal by blocking mating between a negative terminal of the battery and a positive input voltage terminal of the converter.
 12. The method of claim 1, wherein the battery powered device includes the converter.
 13. A battery sleeve for extending the operational life of one or more batteries, the battery sleeve comprising: a positive conductive electrode; an insulating layer extending below the conductive electrode such that when the sleeve is coupled to the one or more batteries, the positive conductive electrode is positioned above a positive terminal of the one or more batteries with the insulating layer electrically isolating the positive conductive electrode from the positive terminal; and a voltage regulation circuit adapted to receive a voltage provided by the one or more batteries and generate an increased output voltage on the positive conductive electrode relative to the provided voltage for at least a portion of the operating life of the one or more batteries.
 14. The battery sleeve of claim 13, wherein voltage provided by the one or more batteries decreases over the operational life of the one or more batteries from a battery first output voltage to a battery second output voltage that is less than 70 percent of the battery first output voltage.
 15. The battery sleeve of claim 13, wherein the voltage regulation circuit outputs the voltage provided by the one or more batteries to the positive conductive electrode as the voltage provided by the one or more batteries decreases from a battery first output voltage to a voltage equal to or greater than a minimal voltage level that the battery powered device requires to operate normally.
 16. The battery sleeve of claim 13, wherein the voltage regulation circuit generates an output voltage greater than the voltage provided by the one or more batteries, the output voltage generated by the voltage regulation circuit decreasing during a portion of the operating life of the one or more batteries.
 17. The battery sleeve of claim 16, wherein the voltage generated by the voltage regulation circuit decreases by less than 10 percent and the voltage provided by the one or more batteries decreases by greater than 30 percent during the portion of the operating life of the one or more batteries in which the voltage generated by the regulation circuit decreases.
 18. The battery sleeve of claim 13, wherein the voltage generated by the voltage regulation circuit is less than the voltage provided by the one or more batteries during an initial portion of the operating life of the one or more batteries.
 19. The battery sleeve of claim 13, wherein: the voltage regulation circuit comprises a step-up converter and a step-down converter that are controlled such that the voltage generated by the voltage regulation circuit is: a) less than an initial voltage provide by the one or more batteries during the operating life of the one or more batteries, b) greater than a final voltage provided by the one or more batteries at the end of the operating life of the one or more batteries, and c) varies by less than 10 percent during the operating life of the one or more batteries; and the final voltage provided by the one or more batteries is less than 70 percent of the initial voltage provided by the one or more batteries.
 20. The battery sleeve of claim 13, wherein the one or more batteries comprises a plurality of separate batteries connected in series.
 21. The battery sleeve of claim 13, wherein the one or more batteries includes a 9 volt battery having standardized adjacent output terminals.
 22. The battery sleeve of claim 13, further comprising a u-shaped element configured to accommodate the positive terminal of the one or more batteries when the battery sleeve is coupled with the one or more batteries and to block electrical connection between the voltage regulation circuit and a negative terminal of the one or more batteries so as to prevent polarity reversal in the voltage provided by the one or more batteries to the voltage regulation circuit. 